Various types of electronic devices, such as spectrum analyzers, usually have multiple input signals. One such input signal, which is generally referred to herein as a reference signal, is typically used to adjust for gain variations over time and temperature. However, because it is often significantly expensive to design and build an accurate and leveled source at many frequencies, the reference signal is usually a fixed source signal at a relatively low frequency such that its complexity and cost can be at least somewhat controlled. This source is typically calibrated in connection with being generated at the factory.
Accordingly, there remains a need for improved electronic device designs that do not require a discrete reference signal input.